The present disclosure herein relates to an electronic device, and more particularly, to a data transmission/reception device for human body communication, a preamble generation method thereof, and a frame synchronization method thereof.
Human body communication uses a human body having conductivity as a communication channel. Data is transmitted using a transmitter connected to a portion of a human body or being outside the human body. The data transmitted through the human body as a medium is recovered using a receiver connected to another portion of a human body or being outside the human body. When human body communication is used, communication between mobile devices or communication between a fixed device and a user may be performed through a contact of a user. For example, communications between a mobile device, such as a digital camera or a smartphone, and a peripheral electronic device may be performed through a contact of a user. Printing, credit card payment, TV reception, entrance control system, or transportation fee payment at the time of riding, etc. may be performed through a contact of a user. In addition, communication with electronic devices attached to the human skin or inserted into the human body may be performed by adopting the human body as a medium.
The air transmits radio waves isotropically, while the human body transmits radio waves anisotropically. Accordingly, a receiver existing at an arbitrary position in the human body is hard to receive accurate radio waves from a transmitter. Radio waves transmitted through the human body lose greater energy than radio waves transmitted through the air. Due to conductivity, the human body is easy to receive an interference signal from surrounding environment.
Physical layer architecture and requirements of human body communication are presented in IEEE 802.13.6 (WBAN) standards. When a frequency selective digital transmission (FSDT) scheme of the wireless body area network (WBAN) standards is used, data transmission at a maximum data rate of 1.3125 Mbps is enabled. However, according to such a method, a spectral efficiency becomes limited to maximum of 0.25 bps/Hz on the basis of a 3 dB bandwidth (5.25 MHz) presented by a transmission mask.
When a transmission filter for satisfying the transmission mask and a reception filter for removing noise from a receiver are used, intersymbol interference (ISI) occurs by the filters. Accordingly, there occurs a problem that bit error rate (BER) performance is degraded.
In addition, when a digital signal is transmitted and received over a network in which a human body is used as a medium, a high spectral efficiency is important. In order to achieve a high spectral efficiency, a preamble structure for transmission frame synchronization and a frame synchronization detection algorithm are required to be premised. Furthermore, a data transmission/reception device and method are required which may improve BER performance with low implementation complexity and low decoding complexity of a received signal.